Thomas M. Turner's Tech Ramblings  

Google’s Gmail web-based e-mail service allows one to download their Gmail account messages via POP3.

Once logged into your Gmail account, click on “Settings” and then click on “Fowarding and POP”.
“Enable POP” and choose how you want downloaded messages to behave (stay in Gmail’s inbox, move to the archive folder, or send to trash). 

The last step is to go into your e-mail client of choice and configure it to download your Gmail messages. Google provides a link with configuration instructions for various e-mail clients, including Mozilla Thunderbird.  One client they do not explicitly list instructions for, however, is Pegasus Mail, although they do provide the necessary information under the “Other” Mail Clients link that should work with any modern e-mail program.

In order to use Pegasus Mail to get Gmail messages, you must have version 4.11 or later, which first included SSL support. 
(Note that I have only tested this on version 4.21c which is the latest version currently available, as I write this.)

To configure Pegasus Mail to download Gmail messages via POP:

• Click on the [Tools/Internet Options] menu, click on the “Receiving (POP3)” tab, click the [Add] button, and click the [New] button.
• Type a name for this new Pegasus Mail POP3 definition, such as “Gmail”.
• Server host name: pop.gmail.com
• Username and password is of course the credentials to your Gmail account.
• Server TCP/IP port: 995
• Click on the “Security” tab and select the “Via direct SSL connect” option.
• I also recommend check-marking the “Enable server certificate fingerprint tracking” option.

That’s it! 

Now, I’m not going to go fully into how to send out e-mail through Gmail’s SMTP servers, as that would then lead into writing about Pegasus Mail’s “identities” feature, to use it in a way that would make any sense. I assume existing Pegasus users have their outgoing e-mail configured to use their ISP’s SMTP server or, in my case, sometimes I also use my employer’s SMTP server (which really only makes sense for me, because my default Pegasus Mail identity uses my work e-mail address as my “Internet e-mail address”.)

For those who just want to know how to configure Gmail SMTP use in Pegasus Mail, though, it works by either setting the “Server TCP/IP port” to 587 and selecting the “Via STARTTLS”  or  by setting the “Server TCP/IP port” to 465 and selecting the “Via direct SSL connect” option.  Regardless of which port and security option one chooses, the “Server host name” is smtp.gmail.com and one of the “SMTP Authentication” options must also be properly configured (the easiest is to use the “Login to the SMTP server using a POP3 username/password” and selecting the POP3 definition created above.)